1. Field of the Invention
The present invention relates to a boost controller that controls a boost circuit for boosting a battery power supply and supplying the boosted power to a load, and to an electronic apparatus that includes the boost controller.
2. Description of the Related Art
Light-emitting diodes (LED) of various types are used in battery-driven portable equipment such as cell phones and personal data assistants (PDA). For example, an LED is used as backlight for a liquid crystal display (LCD). Lithium-ion batteries are commonly used in battery-driven portable equipment. A lithium-ion battery generates a battery voltage of about 3.1-4.2V. A white LED requires a driving voltage of about 3.3-4.0V. Therefore, a charge pump circuit is required to boost the battery voltage. Patent document No. 1 discloses a method of controlling a charge-pump regulated dc-dc converter.